Pain management remains an area of heightened concern for the health care industry. The most prevalent and traditional method of pain management is nurse-administered analgesia. Analgesic describes a medication that alleviates pain. Nurse-administered analgesia typically results in larger and less frequent doses of pain medication than more modern methods. This form of dosing can lead not only to less efficacious pain control but also significant complications like over-sedation, respiratory depression and death.
More recently, patient-controlled analgesia (“PCA”) and patient-controlled epidural analgesia (“PCEA”) have become the preferred methods of administering analgesic as they allow the patient to uniquely control his or her own pain. These devices and similarly operative devices, in which a patient manages his or her pain, are collectively referred to herein as “PCA” devices. In comparison with the nurse-administered analgesic method, the PCA is designed to allow delivery of a smaller amount of analgesic in a more frequent dosing pattern. Typically, a PCA device is set up next to the patient and is programmed by a nurse or authorized caregiver to deliver certain analgesics to the patient upon the patient's command or request. To receive the command, there is typically a cable or wire attached to the device with a button on the end that extends to the patient. The patient can press the button to give a prescribed amount of intravenous or epidural analgesic to him or herself.
It is thought by some in the health care industry that patients can develop a synergism with the PCA device and can effectively manage their pain with less medication thus decreasing side effects like pruritis, dysphoria, hypotension, hypoventilation, bradycardia, and nausea/vomiting. In addition, the PCA device prevents overmedication, and therefore, significantly reduces the risk of cardiopulmonary compromise (e.g., respiratory depression) and death. In the advancement of pain management, then, many PCA type devices have been released on the market and have become a popular form of pain management. Early models usually consisted of a syringe pump connected to a timing mechanism used as a safeguard to prevent an overdose. At the push of the button by the patient, pain medication is administered in small bolus doses assuming a minimum amount of time between each dose has expired. More modern PCA devices include microprocessors to digitally manage lockout intervals and dosage amounts, yet such devices still operate with a simple push button command.
Even with the advancement of modern PCA devices, some patients are still receiving too much analgesic, therefore leading to life-threatening complications. While it is typically believed that a sedated patient will not press the button to deliver more medication, family members, caregivers, and sometimes clinicians are administering the analgesic for the patient by “proxy,” (also referred to herein as “PCA by proxy”) hoping to keep the patient comfortable. This well-intentioned effort has been reported to lead to major complications, up to and including death. Indeed, the Joint Commission on Accreditation of Healthcare Organization (“JCAHO”) has recognized the importance and danger of PCA by proxy and issued a sentinel event alert concerning the issue on Dec. 20, 2004.
One current approach to addressing PCA by proxy is to educate the healthcare industry, patients, families, and visitors to the hazards of improper PCA use. Another approach is provided in U.S. Pat. No. 6,899,695, entitled “Medication Security Apparatus and Method,” given to Herrera, which uses a voice sound recognition algorithm to create a voice print that distinguishes the patient's voice command from other voices to ensure that only the patient controls the bolus dose to himself or herself.
There continues to be a need for improved pain management. Unlike the traditional nurse-administered methods of pain management, with PCA devices, the patient provides a measure of safety him or herself because an over-sedated patient will not be capable of pushing the PCA button. Thus, the previous doses can “wear off” by the processes of redistribution and elimination effectively moving the patient towards safety rather than overdose and complication. PCA by proxy has been identified as a significant breakdown of this effective and otherwise safe device. A need still exists to significantly reduce or eliminate the risk of PCA by proxy in a way that provides a seamless transition from current methods and can be used effectively in a hospital or other patient care setting.